Oil well pumping apparatus



F. w.-P1 E'UGER OIL. WELL PUMPING APPARATUS FiledJuly 1o, 1957 Match 4,1958 R 6N mfp/W ATTORNEYS mf `E V N u, 7NM 3 .70 7 Z Z 3 Z. 2,2 @Y o V MM /0 A EJ 2 V 4 i y 5. 5 a, H//3% y United States Patent() OIL WELLPUMPING APPARATUS Friedrich Wilhelm Pleuger, Hamburg, GermanyApplication `Iuly 10, 1957, Serial No. 670,946 Claims priority,application Germany January 11, 1957 6 Claims. (Cl. 103158) Thisinvention relates to pumping apparatus for oil wells and is particularlyconcerned with pumping equipment for use in the handling of relativelyheavy or highly viscous oils.

The invention employs a hollow piston which is slidably mounted on theouter surface of a hollow cylinder, the latter in turn being secured tothe well riser. lower end of the piston is provided with a knife-likeend for facilitating its entry into the viscous oil. Interiorly thehollow piston also carries a apper valve which is opened during downwardmotion of the piston and closed tion being imparted by a reciprocatingpiston rod which extends to the surface. The invention also employs asuitable check valve above the apper valve which check valve opensupwardly to permit passage of the oil and The f seats downwardly toprevent the oil from running back rod is centrally guided in the hollowcylinder and has limited relative movement with respect thereto, theapper valve being alternately'opened and closed upon each reversal ofthe motion of the piston rod.

YIt is also an object of the invention to provide the ratherconsiderable rod power which is necessary to deliver the heavy viscousoils of the type for which the pump is designed, and, at the same time,to operate the apper valve with a minimum kof wear on the valve and itsseat. To this end the invention provides improved articulation betweenthe actuating piston rod on the one hand'and the hollow piston and theflapper valve on the other hand so as to greatly minimize the'strainsimparted to the flapper valve and its seat during operation of the pump.

In attaining the objectives above mentioned the piston rod is guided ina cross head which isrrigidly connected to the interior of the hollowpiston, through which cross head theY piston rodhas a limited degree ofsliding movement with respect thereto. At its lower end the piston rodis also provided with a suitable enlargement for supportingthe hollowpiston duringthe upward kstroke of the piston rod after closing movementof the tlapper valve has been initiated. In this way the apper valve andits actuating parts are stressed by the power of the piston rod onlyduring a relatively small part of the delivery stroke, because,immediately following the start of the upward stroke, the hollow pistonwith its cross head is' supported directly on the piston rod itself.

How the foregoing objectives, together with such other objectives andadvantages as are incident to my invention are attained is illustratedin preferred form in the accompanying drawing wherein:

Figure 1 is a vertical longitudinal section through my improved pumpingequipment with the parts in the po- 2,825,288 Patented Mar. 4, v 1958ICC sition they assume during the downward stroke of the piston rod; and

Figure 2 is a similar section on an enlarged scale of the lower portionof the pumping equipment illustrated in Fig. 1 with the parts in theposition they assume during the upward or delivery stroke of the pistonrod.

The pump housing is formed essentially as a hollow cylinderV 1 which isthreaded to a coupling member 2 by means of which it can be connected tothe customary riser 3, ythe connection between the coupling and theriser being provided for by a tapering thread 4. The screw connection 5between the hollow cylinder 1 and the coupling 2 is packed with a gasket6.

A hollow piston 7 is slidably mounted on the hollow cylinder 1 and atthe upper end of the hollow piston there isa stuffing box 8 which can betightened by means of a screw ring 9. At the lower end of the hollowpiston 7 is arranged a cross arm or cross head 10 within which is aguide bushing 11 through which the lower end of the operating piston rod12 is adapted to slide.

The piston rodV 12 is extended axially through the hollow cylinder 1 andis provided at its upper end with a coupling 13 with which it can beconnected to a pump actuating rod of-the usual type of construction. Theapertured abutment 14`is a further guide for the piston during upwardmotion said upward and downward mo .I rod .12 which abutment 1s rigidlysecured within the hollow cylinderv 1 and is equippedwith abushing 15through which .the piston rod reciprocates.` The flap valve withinthehollow piston takes the form of a butterfly valve 16 and this valveis arranged near the lower knife-like end 38 of' the hollow piston. Thevalve 16 is mounted pivotally on a pin 17 mounted at opposite ends inthe'walls ofthe hollowpiston 7. Rigid withv the butterilyvalve 16 is aswivel arm 18 is connected and this arm has an oblong hole 19 whichcooperates with the pin or bolt 20, the latter being arranged tov moveback and forth in the hole 19.. During downward movement of the rod 12the pin slides into position where a torque is attained around the axisof the pin 17 which torque vopens the buttery valve 16. During downwardmovement of the rod the bolt-20 slides back into its original positionthe arrangement being such that there is. little if any stress placedupon the parts so that .deflection or bending of the pump rod12 isavoided.

By means of the bolt 20 and a fork 21 a spring plunger a 22 projectsupwardly into a socket 23, which latter is f or toward each other.

closed with a connection nut 24. Between the connection nut 24 and anabutment on the end of the spring plunger 22, a compression spring 25 isinserted which biases the spring plunger 22 and the socket 23 togetherThe socket 23 has a plurality of equalizing openings 26 by which the oilbeing pumped can enter on both sides of the end of the spring plunger.

The piston rod head 27, which is screwedv to the rfree end of the pistonrod by means of a Ythread 28 and is secured in position by means Vof abolt 29, constitutes the connecting linkbetween the socket 23 and thelower end of the piston rod 12, the lower end of the piston rod head 27being pivotally connected with the spring socket 23 by the connectionbolt 30.

Above the cross head 10, there is provided a ring shaped valve seat 31within the hollow cylinder 1 and this valve seat cooperates with acone-shaped valve member 32 having a central opening by means of whichit is arranged to surround the piston rod 12 and slide with respectthereto. To provide for satisfactory packing of the valve member 32 withrespect to the piston rod 12, a stuffing box is arranged in the interiorof the valve member 32 which consists of C-ring packing 33 and a screwnipple 34. The screw nipple 34 is provided with a sleeve-like projection35 on which the closing spring 36' of the check valve is guided. Theabutment 14 is provided with openings for passage ofthe oil, and thisabutment serves as a support for one end of the closing spring 36,aswell as forl guiding lthe piston rod,12 in its .bushing 15.

The abutment 14 serves additionally as a means. for limiting the pumpstroke in the lower dead center. On the upper side of the abutment piece14', a crown-shaped projection 39 is provided which cooperates with acrownshaped projection 40 on the upper end of `the rod in the immediatet vicinity of the rod screw connection 13. These two crown-shapedprojections are arranged to prevent initial angular movement ininstallation and disassembly of the pump. This provides a safety factorin that in loosening the screw connections of the rods, the turning ortwisting movement of the piston rod 12 with respect to the remainingparts of the pump, is prevented.

Operation of the equipment may be summarized as follows. The pump isintroduced in vertical position into the petroleum bore hole and thecoupling 2 is screwed to the lower end of the customary well riser. Thecoupling 13 of the piston rod is connected with a motor driven upwardlyand downwardly reciprocating actuating rod in the usualmanner.

In the downward motion of the piston rod 12 the parts of the pump assumethe positions indicated in Figure 1. Here` thepiston rod head 27 isseparated from the cross head and by means of the two-piece intermediate lever 22,23 the buttery valve 16 is swung until itcomes to itsfully opened position against its stop 37 in the hollow piston. Byvirtue of the power transmitted from the piston rod 12 by means of theinter,- mediate lever 22, 23 as well as by the buttery valve pin 17 andalso by its own weight, the hollow piston 7 is moved downward to pressits sharpened end `38 into the viscous heavy oil to be delivered fromthe well.

After the piston rod reaches `its lowest point the direction of movementchanges and it begins to move upwardly and the initial upward movementoccurs without` takingl along the hollow piston 7 because the piston rodhead 27 is not yet in position at the cross head 10. In this initialmovement of the piston rod, the buttery valve 16 is moved from its open`position shown in Fig. 1 toward the closed position shown in Fig. 2.Because the viscous oil offers considerable resistance to movement ofthe buttery valve 16, the closing of this valve can occur somewhat moreslowly than it would in the event that the parts were rigidly fixed toeach other. The difference of speed between the rotating movement of thebuttery valve 16 and the stroke movement of the piston rodis compensatedfor by the compression spring 25 in the two-part intermediate lever 22,23'.` By virtue of this spring arrangement 25, the closing ofthe butteryvalve can occur somewhat delayed and can be continued after the pistonrod head 27 has already engaged the cross head 10. The stud boltconnection 19, 20 compensates for relative movement and serves to assuresatisfactory closing of the butterfly valve 16 under the influence ofthe spring 25.

After the tlap valve 16 is closed and the piston rod y 4 head 27actuates the cross 7 together with the quantity of heavy oil trappedtherein by the buttery valve 16 is moved upward with respect to thestationary hollow cylinder 1. This forces the heavy oil past the crosshead 10, through the central valve seat 31, and raises the valve cone 32against the pressure of the spring 36, the valve 32 seating downwardlyto prevent runback after reversal of the piston rod stroke. Above the`valve conek 32, the oil moves upward through the bore in the abutment14 and then along side of the piston rod 12 and past the connection 13to and through the riser 3 until it reaches the surface.

I claim:

1. Pumping apparatus for an oil well having a riser and a piston rod,`comprising a hollow cylinder secured to the riser, a hollow pistonslidably mounted on the outer surface of the cylinder, a cross head forthe piston rod secured to the inner wall of the hollow piston, saidpiston rod being mounted to project through and to slide with respect`to the cross head, an enlargement securedV to the piston rod below the`cross head, which enlargement is adapted to be moved away from the crosshead on the downward stroke of the piston rod and to be returned toengage the cross head on the upward stroke of the piston rod, wherebythe hollow cylinder is supportedby the piston rod, a ap valve inthehollow piston below the cross head, said tlap valve being adapted tocontrol ow through the hollow piston, a resilient operating connectionbetween the ap valve and the end of the pistonrod, said Hap valve andits operating connection being constructed and arranged to effectopeningof the valve upondownward movement of the piston rodgand closingthereof upon `upward movement of the piston rod, and an upwardly openingcheck valve above the cross, head.

2.` Pumping apparatus according to claim 1 wherein the flap valve isformed as a butterfly valve and wherein the operating connectionincludes a pair of telescoping members with resilient means biasing themtoward each other.

@Pumping apparatus according to claim 2 wherein one telescoping memberis joined to the `butterfly valve by a pin guided in an elongated hole.

4. Pumping apparatus according to claim l wherein the check valveslideson the piston rod and seats on a ring-shaped seat secured to the hollowcylinder.

5. Pumping apparatus according to claim 4 wherein the check valve isprovided with a stuing box and packingarourid` the piston rod.

6. Pumping apparatus according to claim 4 wherein an` abutment member isfixed in the hollow cylinder above the checktvalve and, further, whereina spring reacts between said abutment member and the check valve.

vReferences Cited `in the le of this patent STATES PATENTS 2,630,757Cartier Mar. l0, 1953 FOREIGN PATENTS 23,271 Great Britain Nov. 30, 1894head 10, the whole piston`

